What happened iRobot (NASDAQ: IRBT) stock trailed the market by a wide margin last month, falling 20% compared to a 1% uptick in the S&P 500, according to S&P Global Market Intelligence. That slump contributed to a roller-coaster ride for shareholders, who had been up by 60% at one point in 2019 but are now looking at declines of nearly 20% for the year. Image source: Getty Images. So what Investors reacted harshly to the robotic cleaning device specialist's second-quarter report that showed slowing sales growth and spiking costs. iRobot said in late July that sales came in below expectations for the period even as expenses jumped. Management blamed both issues on what they believe will be temporary dislocations caused by rising tariff rates. Now what CEO Colin Angle and his team see plenty of support for their bullish long-term reading of the industry, including strong demand for iRobot's latest product launches. However, investors are likely to see mounting disruption from the tariff increases in the months to come, including a shift in order volumes toward later in the year. That factor will put even more pressure than normal on this consumer-focused industry during the make-or-break holiday season quarter in 2019. 10 stocks we like better than iRobotWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has quadrupled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and iRobot wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 1, 2019 Demitrios Kalogeropoulos has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends iRobot. The Motley Fool has a disclosure policy.Source